Holmium vs Protactinium
| Property | Ho Holmium | Pa Protactinium |
|---|---|---|
| Atomic number | 67 | 91 |
| Symbol | Ho | Pa |
| Name | Holmium | Protactinium |
| Category | lanthanide | actinide |
| Standard Atomic Weight | 164.93033 u | 231.03588 u |
| Period | 6 | 7 |
| Group | N/A | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s24f11 | [Rn]7s25f26d1 |
| Oxidation states | [0, 1, 2, 3] | [2, 3, 4, 5] |
| Electronegativity (Pauling) | 1.23 | 1.5 |
| Electron affinity | 0.338 eV | 0.123 eV |
| Density | 8800 kg/m³ | 1.537000e+4 kg/m³ |
| Melting point | 1473.85 °C | 1571.85 °C |
| Boiling point | 2699.85 °C | -273.15 °C |
| Discovery year | 1878 | 1913 |